Varying Failure Criteria on Performance Validity Tests Influences Interpretation of Cognitive Outcomes

Objective: The present study examined the effects of applying various performance validity tests (PVT) failure criteria on the relationship between cognitive outcomes and posttraumatic stress (PTS) symptomology. Method: One hundred and ninety-nine veterans with a history of mild traumatic brain injury referred for clinical evaluation completed cognitive tests, PVTs, and self-report measures of PTS symptoms and symptom exaggeration. Normative T scores of select cognitive tests were averaged into memory, attention/processing speed, and executive functioning composites. Separate one way analyses of variance assessed differences among high PTS (n = 140) versus low PTS (n = 59) groups and were repeated excluding participants based on varying combinations of PVT failure criteria. Results: When no PVTs were considered, the high PTS group demonstrated worse performance across all three cognitive domains. Excluding those who failed two or more stand-alone, or two or more embedded validity measures resulted in group differences across all cognitive composites. When participants were excluded based on failure of any one embedded and any one stand-alone PVT measure combined, the high PTS group performed worse on the executive functioning and attention/processing speed composites. The remaining three proposed methods to control for performance validity resulted in null PTS-cognition relationships. Results remained largely consistent after controlling for symptom exaggeration. Conclusions: Methods of defining PVT failure can greatly influence differences in cognitive function between groups defined by PTS symptom levels. Findings highlight the importance of considering performance validity when interpreting cognitive data and warrant future investigation of PVT failure criteria in other conditions. Key Points Question: Does choice of performance validity criteria impact interpretation of cognitive results? Findings: Results suggest that interpretation of neurocognitive data can be greatly influenced by the choice of performance validity test failure criteria applied. Importance: Findings highlight the importance of considering performance validity when interpreting cognitive data within clinical and research settings alike. Next Steps: Results warrant future investigation of performance validity tests failure criteria in other conditions.